How lightning fertilizes soil with atmospheric nitrogen fixation

NORFOLK, Va. — When most people think of lightning, they picture bright flashes in the sky or the rumble of thunder that follows. But lightning does more than put on a show during storms: it helps fertilize the earth.

The air around us is filled with nitrogen gas, making up 78% of the atmosphere. But it exists in a form that plants cannot use. In the atmosphere, nitrogen exists as two very tightly bonded atoms, N2.

For plants to process that nitrogen, the two atoms must be separated.

A lightning strike provides the spark needed to change that. Each bolt carries enormous energy, hot enough to split apart nitrogen molecules in the air.

Once separated, nitrogen atoms combine with oxygen to form nitrogen dioxide, NO2. These compounds mix with water in the atmosphere, turning into nitrates,